The present invention relates to wireless communication systems in general, and particularly relates to base station architectures for next generation CDMA radio access networks.
Most first and second-generation CDMA radio access networks use proprietary network architectures and protocols to provide interconnection between the core of the radio access networks (e.g. MSC) and the base transceiver stations (BTSs). One such proprietary network is known as the base communication network (BCN). A BCN employs a star-cluster topology in which clusters of processing devices are attached to each leg of the star. Base station controller (BSC) functionality is distributed among these processing devices. Some level of robustness is achieved in the BCN architecture by distributing mission critical functions on different legs of the star, and by using a redundant hub that constantly monitors its own health.
Demand for wireless services has increased dramatically in recent years. This increased demand has exposed a number of limitations in the BCN architecture. The BCN links are limited in bandwidth to about 10 Mbps. The BCN transport bandwidth places a ceiling on the number of Erlangs that can be supported and the physical volume of equipment required to increase call volume further makes it impractical to evolve the architecture. In addition, because multiple devices share the same BNC links, which are not fault tolerant, a transport failure can result in a significant number of dropped calls. Also, a proprietary communication protocol requires the use of special analyzers to observe information flow and monitor performance of the radio access network.